Calculator Using Visualforce page

Controller Code :-

public class Calculator {

    Public Integer Number1{get;set;}
    Public Integer Number2{get;set;}
    Public integer Result{get;set;}

    public PageReference Subtraction() {
        Result= Number1 - Number2;
        return null;
    }


    public PageReference Addition() {
        Result= Number1 + Number2;
        return null;
    }
    
    public PageReference Division() {
        Result= Number1 / Number2;
        return null;
    }
    
    public PageReference Multiplication() {
        Result= Number1 * Number2;
        return null;
    }
    
    

}

Visualforce Page :-

<apex:page controller="Calculator">
  <apex:form >
  <apex:pageBlock >
  <apex:pageBlockButtons >
  <apex:commandButton value="Add" action="{!Addition}" reRender="refresh"/>
  <apex:commandButton value="Sub" action="{!Subtraction}" reRender="refresh"/>
  <apex:commandButton value="Divide" action="{!Division}" reRender="refresh"/>
  <apex:commandButton value="Multiply" action="{!Multiplication}" reRender="refresh"/>
  
  </apex:pageBlockButtons>
  <apex:outputPanel id="refresh">
  <apex:pageBlockSection columns="2">
  <apex:outputLabel value="Number 1"/>
  <apex:inputText value="{!Number1}"/>
  <apex:outputLabel value="Number 2"/>
  <apex:inputText value="{!Number2}"/>
  <apex:outputLabel value="Result"/>
  <apex:inputText value="{!Result}"/>
  </apex:pageBlockSection>
  </apex:outputPanel>
  </apex:pageBlock>
  </apex:form>
</apex:page>

OutPut Screen 1 :-